Three different systems for forming cable dead-ends are commonly in use today in the art. These are a molten metal system, the resin system, and a wedge type ferrule system.
In the molten metal system, the cable end is cleaned with three different solutions to remove grease and oil, etch the wire, and neutralize the etching acid. Then the wire end is broomed out, a suitable metal (babbit or zinc) is heated over an open flame, and the molten metal is poured on the broomed end and allowed to cool to provide the finished product. In the resin system, a wire seizing is disposed on the cable a predetermined distance from the cable end, the cable end is cleaned, care being taken to insure that a solvent that is compatible with the resin to be used is employed, the end is broomed, a socket disposed therearound, and the broomed strands in the socket interior filled with resin, with a final cure taking approximately sixteen hours at room temperature, and care being taken to see that the method is not practiced when the socket temperature is below 65.degree. F. or above 100.degree. F. In the wedge type ferrule system, a ferrule is slipped over the cable, the strands are unwound, an insert is disposed over the cable core strand, the strands are rewound around the core, and the wedge is hammered into place in the ferrule so that a tight interference fit is provided between the wedge, strands, and ferrule.
While each of the above systems can be utilized to provide an acceptable cable dead end, they have one or more of the following problems associated therewith: The use of multiple solvents, or a restricted number of solvents may be utilized. The requirement for cable brooming. The utilization of an open flame, which in some work places is dangerous and/or inconvenient. Excessive loosening when the load is released. Excessive susceptibility to corrosion. The necessity for long curing times, or special curing equipment.
According to the present invention a method of forming a cable dead end is provided which overcomes essentially all of the above mentioned disadvantages associated with conventional prior art arrangements. According to the present method, a cleanly cut cable end is provided, a ferrule is slipped over the cable end onto the cable, and the cable strands are unwound and separated (a screwdriver may be utilized to accomplish this) over a length of the cable from the cable end to the ferrule, and the strands of the cable are disposed in a general bird-cage configuration. Then an insert (preferably barbed) is slipped over the core strand disposed within the bird-cage configuration, and the ferrule is also moved over the bird-cage configuration into the end of the cable. Then the void space inside the ferrule, between the strands, ferrule, and insert, is packed with a metallic void-filling material, preferably steel wool. Then the cable strands, insert, and metallic void-filling material inside the ferrule are saturated with an anerobic, structural, single component adhesive that can fast-cure at room temperature.
The ends of the ferrule may be sealed, as with a rubber cap, O-ring, hose clamp, and the like. During saturation of the interior of the ferrule, the open end of the ferrule may be sealed, the cable inverted, and the adhesive poured through a bore in the ferrule, so that leakage of adhesive from the ferrule is minimized.
According to the present invention, a cable dead end of a steel multi-strand cable (including a core strand) is provided. The dead end comprises a ferrule having an elliptical interior cross-section, and an insert disposed around the cable core strand with the other cable strands disposed around the insert in a bird-cage configuration, and with the insert substantially centered in the ferrule interior. The insert also may be generally elliptical in cross-section with barbs on the exterior surface thereof, and the ferrule is packed with steel wool, and the interior is saturated with an anerobic, structural, single component adhesive.
It is the primary object of the present invention to provide an improved method for forming a steel cable dead end, and an improved resulting cable dead end. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.